1. Field of the Invention
The present invention relates to a fan, and more particularly, to a fan having a dust-proof apparatus installed at a suction hole thereof that is capable of preventing insects or dust from being introduced together with air.
2. Description of the Background Art
A fan generating fluid flow such as air flow typically includes a casing having an air flow passage; a drive motor mounted inside the casing and generating a rotational force; and a plurality of blades rotatably installed in the air flow passage of the casing and being rotated upon receipt of a driving force of the drive motor.
In the fan, when the drive motor is operated as a power is applied thereto, the blades are rotated according to the drive motor.
When the blades are rotated, a pressure difference is generated due to the rotation of the blades, and thanks to the pressure difference, air flows along the air flow passage.
The fan is classified into an axial flow fan, a centrifugal fan and a sirocco fan according to air flow passage form.
In case of the axial flow fan, air flow forms a linear flow as air is introduced from a front side and flows to a back side. Meanwhile, in case of the centrifugal fan or the sirocco fan, it forms a curved flow as air is introduced from the front side and flows out to the side.
A fan is used in various fields where the air flowing is required, and an electrodeless lighting system employs it to cool devices installed therein by sucking air from outside.
FIG. 1 is a sectional view showing an electrodeless lighting system having a fan with a dust-proof apparatus.
As shown in FIG. 1, the electrodeless lighting system having a fan with a dust-proof apparatus includes: a casing 10; a high voltage generator 20 mounted at an inner front surface of the casing 10 and generating a high voltage; an microwave generator 30 for generating a microwave with the high voltage generated from the high voltage generator 20; a wave guide 40 for guiding the microwave generated from the microwave generator 30 and serving as a first resonator; a second resonator 50 installed at a front outer side of the casing 10, exciting the microwave guided through the waveguide 40 and generating a strong electric field; an electrodeless lamp 60 rotatably mounted inside the second resonator 50, forming a plasma as a gas filled therein is excited according to the strong electric field of the second resonator 50, to thereby generate a light; a first mirror 70 positioned at a rear face of the electrodeless lamp 60 and reflecting the light generated from the electrodeless lamp 60 to the front surface; and a second mirror 80 for collecting the light generated from the first mirror 70 and the electrodeless lamp 60 and reflecting it to the front side.
The casing 10 includes a lamp driving motor 90 for rotating the electrodeless lamp 60 to cool the electrodeless lamp 60 and a connection shaft 91 for connecting the lamp driving motor 90 and the electrodeless lamp 60.
At one side of the casing 10, a passage 11 is installed allowing air to flow toward the microwave generator 30 and the high voltage generator 20. An entrance 12 is formed at one side of the passage 11, into which an external air is introduced, and a fan 100 is mounted at the inner side of the entrance 12.
The fan 100 includes a plurality of blades 101 for generating air flowing by rotation and a fan driving motor 110 for rotating the blades 101.
The operation of the electrodeless lighting system will now be described.
First, when a power is applied to the high voltage generator 20, the high voltage generator 20 generates a high voltage, and the microwave generator 30 generates microwave according to the high voltage generated from the high voltage generator 20.
The microwave generated from the microwave generator 30 is transferred to the second resonator 50 through the wave guide 40, so that a strong electric field is distributed at the second resonator 50, and according to the strong electric field, the substance filled in the electrodeless lamp 60 is discharged, and at the same time, vaporized to generate plasma.
The light emitted as the plasma is generated from the electrodeless lamp 60 is reflected by the first mirror 70 and the second mirror 80 and illuminated forwardly.
At this time, much heat is generated from the high voltage generator 20 and the microwave generator 30.
The intense heat generated from the electrodeless lamp 60 is cooled by rotating the electrodeless lamp 60 by the lamp driving motor 90.
When the blades 101 are rotated as the fan driving motor 110 is operated, an external air is introduced through the entrance 12 due to the pressure difference according to the rotation of the blades 101.
The external air introduced into the entrance 12 is guided through the passage 11 and flows while passing the high voltage generator 20 and the microwave generator 30 to cool the high voltage generator 20 and the microwave generator 30.
Meanwhile, in the process that the conventional fan 100 having the dust-proof apparatus mounted at the electrodeless lighting system is operated, insects such as a day-fly, mosquito and a moth gather, and the gathered insects and dust are introduced into the passage 11 together with the external air due to the suction force of the fan 100 to be compressed to the fan 100 or attached to a part inside the casing 10, interfering the rotation of the fan 100 or damage the internal parts.
In order to solve the problems, a dust-proof is provided at the side of the entrance 12 where the external air is introduced.
FIG. 2 is an enlarged sectional view of FIG. 1.
As shown in FIG. 2, the dust-proof apparatus of the fan includes a dust-proof member 120, and a screw 130 for engaging the marginal portion of the dust-proof member 120 to the casing 10 so as for the dust-proof member 102 to be fixed.
Though insects or dusts are restrained from being sucked into the casing 10 as they are caught by the dust-proof member 120 in the process that external air is being introduced due to the pressure difference according to the rotation of the blades 101, the conventional fan having the dust-proof apparatus is disadvantages in that insects or dusts are collected at the surface of the dust-proof member 120, causing a reduction of air flowing and increase in an air suction resistance.
FIG. 3 is a vertical-sectional view of a different fan having a dust-proof apparatus, and FIG. 4 is a plan view of the fan having a dust-proof apparatus of FIG. 3.
As shown in FIGS. 3 and 4, Japanese Laid Open Publication No. JP2000161734 discloses another example of the fan having a dust-proof apparatus, in which a guide duct 200 is insertedly fixed at an outdoor opening of a ventilation duct (D), a fixing member 210 having a bearing 211 is insertedly combined inside the guide duct 200, and a propeller 220 rotated by wind is rotatably coupled at the bearing 211 of the fixing member 210.
The cylindrical dust-proof member 230 is fixedly coupled to a rotational shaft 221 of the propeller 220 to cover the front portion of the propeller 220, and a fixing member 240 in a xe2x80x9cUxe2x80x9d shape having a certain thickness and width traverses the cylindrical dust-proof member 230 and fixedly coupled to one side of the guide duct 200.
In the conventional fan having the dust-proof apparatus having the structure as described above, as the propeller 220 is rotated according to air flowing in the ventilation duct (D), the dust-proof member 230 coupled to the rotational shaft 221 of the propeller 220 is accordingly rotated to thereby prevent insects or dusts from being introduced into the ventilation duct (D) as well as being attached to the dust-proof member 230.
However, since the cylindrical dust-proof member 230 is fixedly coupled to the rotational shaft 221 of the propeller 220, the fixing state of the cylindrical dust-proof member 230 is not firm with the rotational shaft 221.
In addition, an eccentricity is generated between the propeller 220 and the cylindrical dust-proof member 230 coupled to the rotational shaft 221 of the propeller 220 due to an unbalance according to a roundness and assembly precision. Thus, a noise is generated due to the eccentric rotation of the cylindrical dust-proof member, and the coupling state of the dust-proof member would not last long and the coupling is disassembled.
Moreover, since a fixing member 210 is to be additionally installed at an outer side of the ventilation duct (D) to install a bearing that is rotatably supported by the rotational shaft, its structure becomes complicated.
Therefore, an object of the present invention is to provide a fan having a dust-proof apparatus that is capable of minimizing a noise generation and ensuring a firm coupling state as well as preventing insects or dusts from being introduced according to an air flowing owing to a rotation of a plurality of blades constituting a fan.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a fan having a dust-proof apparatus including: a casing having a passage; a rotation driving unit installed inside the casing; a plurality of blades positioned in the passage and coupled to a rotational shaft of the rotation driving unit so as to be rotated; and a dust-proof member installed at an entrance of the passage to cover the entrance of the passage, and integrally coupled to the blades so as to be rotated together with the blades.
To achieve the above objects, there is also provided a fan having a dust-proof apparatus including: a casing having an entrance and a passage; a rotation driving unit installed inside the casing; a plurality of blades positioned in the passage and coupled to a rotational shaft of the rotation driving unit so as to be rotated; and a dust-proof member installed at an entrance of the passage to cover the entrance of the passage, and coupled to the rotational shaft so as to be rotated together with the blades, wherein an outer circumferential surface of the dust-proof is supported by the entrance so that the dust-proof member is rotatable.
To achieve the above objects, there is also provided a fan having a dust-proof apparatus for an electrodeless lighting system including a casing; a microwave generator mounted inside the casing and generating microwave; a wave guide for guiding the microwave generated from the microwave generator and serving as a first resonator; a second resonator installed outside the casing so as to communicate with the waveguide, and exciting the microwave guided through the waveguide to generate a strong electric field; and an electrodeless lamp mounted inside the second resonator and forming plasma as gas filed inside there is excited by the strong electric field of the second resonator, to thereby generate light, wherein the fan having a dust-proof apparatus includes a passage formed at the casing to suck an external air to cool the electrodeless lighting system; a rotation driving unit installed inside the casing; a plurality of blades installed in the passage and coupled to a rotational shaft of the rotation driving unit so as to be rotated; and a dust-proof member installed at an entrance of the passage to cover the entrance of the passage, and integrally coupled to the blades to be rotated together with the blades.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.